A vendor smokes behind a display of dog meat at a dog meat market on the day of a local dog meat festival in Yulin, Guangxi Autonomous Region, June 22, 2015. (Photo by Kim Kyung-Hoon/Reuters)

A couple photograph The Helmsley Building on Park Avenue, lit in honor of the victims of the Nice attacks, in Manhattan, New York, U.S., July 15, 2016. (Photo by Brendan McDermid/Reuters)

Chinese soldiers leave after Chinese President Xi Jinping inspected troops of People's Liberation Army (PLA) Hong Kong Garrison at the Shek Kong Barracks in Hong Kong, Friday, June 30, 2017. Xi landed in Hong Kong Thursday to mark the 20th anniversary of Beijing taking control of the former British colony, accompanied by a formidable layer of security as authorities showed little patience for pro-democracy protests. (Photo by Kin Cheung/AP Photo)

Alfred the frog looks almost as scary as the pumpkin he is perched on at London Zoo 26 October 2011. Keepers at the zoo have joined in the Halloween tradition by supplying pumpkin lunches to some of their animals, including the giant waxy monkey frog. However Alfred is not quite the giant figure his species name suggests – he actually measures up at around 4 inches (10 centimeters). (Photo by EPA/Zoological Society of London)

An infrared portrait from NASA's Spitzer Space Telescope which shows generations of stars is seen in this undated NASA handout image released February 14, 2013. In this wispy star-forming region, called W5, the oldest stars can be seen as blue dots in the centers of the two hollow cavities (other blue dots are background and foreground stars not associated with the region). Red shows heated dust that pervades the region's cavities, while green highlights dense clouds. (Photo by NASA/Reuters/JPL-Caltech/Harvard-Smithsonian/Handout)

A three-month-old Sumatran tiger cub named “Bandar” shows his displeasure after being dunked in the tiger exhibit moat for a swim reliability test at the National Zoo in Washington, on November 6, 2013. All cubs born at the zoo must take a swim test before being allowed to roam in the exhibit. Bandar passed his test. (Photo by Manuel Balce Ceneta/Associated Press)

1st prize in the People Observed Portraits Stories category. Carla Kogelman, the Netherlands. The photo shows Hannah and Alena, two sisters living in the rural village of Merkenbrechts, Austria. (Photo by Carla Kogelman/World Press Photo)

Actor George Clooney from the film “Ides Of March” arrives at the Hotel Excelsior during the 68th Venice Film Festival on August 31, 2011 in Venice, Italy. (Photo by Gareth Cattermole/Getty Images)